Crystalline silica
US4061724A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1975 |
| Grant date | Dec 6, 1977 |
| Priority date | — |
| Expiry date | Sep 22, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/22
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A novel crystalline silica composition having uniform pore dimensions of approximately 6 Angstrom units is prepared by calcining a crystalline hydrated alkylonium silicate prepared hydrothermally from a reaction mixture containing as essential reagents, water, amorphous silica and a quaternary ammonium compound at a pH of at least 10. The crystalline silica, because of its uniform pore structure, is capable of making size-selective separations of molecular species, but neither it nor its silicate precursor exhibit ion-exchange properties. This absorbent has a very useful hydrophobic/organophilic characteristic which permits its use in selectively adsorbing organic materials from water, either in liquid or vapor phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.